On the Move configuration page, enter a name for the migration batch in the New migration batch name field. Use the down ...

On the Move configuration page, enter a name for the migration batch in the New migration batch name field. Use the down arrow to select the target delivery domain for the mailboxes that are migrating to %BRAND_OFFICE_365_SHORT%. In most hybrid deployments, this will be the primary SMTP domain used for both on-premises and %BRAND_OFFICE_365_SHORT% organization mailboxes. For example, [email protected]. Verify that the Move primary mailbox along with archive mailbox option is selected, and then select Next.